We propose in this investigation to study the cellular interactions occurring during the immune response to Coccidioides immitis in mice. The role of T lymphocytes in the possible activation of alveolar macrophages leading to their increased fungicidal activity will be determined in vitro. It will be determined whether the population of T cells effective in transferring immunity in vivo to an intranasal infection are effector cells or memory cells. In addition the effectiveness of immune lymphocytes or their soluble products in altering the outcome of an ongoing potentially lethal infection in mice when given with subminimal effective doses of amphotericin B will be determined. The proposed investigation should result in more knowledge about the immunological relationship between the host and fungus in coccidioidomycosis and clarify the potential usefulness of chemotherapy-immunotherapy combination in coccidioidomycosis.